Fusible-plug water release



Aug. 1&9, 1930. L. D. LOvEKlN EUsIBLE PLUG WATER RELEASE Filed Oct. 20.1927 lzo hause', and may the prior art.

35 shoulder in the hot water inlet of a Patented Aug. 19, 1930 VUm'rlaznSTATES PATENT OFFICE LurHEB) D. LovExIN, or WYNNEWooD, PENNSYLVANIA AEUsIBLE-PLUG wA'rEn RELEASE Application led October 20, 1927. SerialNo'. 227,391.

the dangerously high fluid pressure incident to abnormally hightemperature and with normal s stems' to permit replacement of .some ofthe very hot water in the heater by water from the cold water supplyline.

I close the inlet to a waste pipe connection .with my heat element,usually making the oonnectlon from vthe top of a boiler, desirably with.a-T yfitting that provides outlet from the 'boiler into the hot watersupply pipe of the desirably mount the heatweakened element betweenad'oining members of a union at the inlet end of the waste P1Pe- Afurther purpose is to cut-heat-weakened element discs from a bar offusible metal and bq accommodate the thickness ofthe discs to.

thearea of outlet and the pressure to which the discs may be subjected,and am thu'senabled to obtain discs inexpensively that have ,Superiorand definite characteristics as compared to those of4 the moldedelements of A further purpose is to clamp a heatweakened element disc toplace a ainst' a dlscharge `1 e by means of a sleeve threaded into the1n et and preferably provided with slots on opposite sides for screwingin or lunscrewing the sleeve.

Further purposes will appear in the specificationand in the claims.

I have referred to illustrate my invention 1 in a few orms onlyselecting forms that are practicaland convenientin operation and whichwell illustrate the principles involved.

l Figure 1 is a fragmentary sectional elevation showing one form of minvention ap plied to a domestic boiler or t e like using an' individualconnection into the boiler for the relief pipe. g

Figure 2 is a fragmentary sectional'eleva-l tion showing the form inwhich the inlet to my relief pipeis supportedfrom a T fitting providinghot water outlet from the boiler.

Figures 3 and 4 are fragmentary sectional elevations correspondingygenerally to Figure 2 but showing modified forms.

Figure 5 is a fragmentary partly sectioned detail showin a differentmountin for the heat-weakene element-from that of gure 2. 6o

Like numerals refer to like parts in all figures.

Describin in illustration and not in limita tion, and re erringto thedrawings My invention is intended particularly' to 65 protect hot waterb0ilers,tanks and other containersa ainst excessive pressures incidentto overheating from any cause 'and accompanied by. abnormally hightemperature within the boller.

In the `Yillustration a heater l0 may com l prise an fluid heater,usually the water heater o a domestic heating system.v 7, .In manysystems any overheatingfin the boiler ma result- .in excessive 4anddangerous .75 pressure'ln the boiler.' Normally overheating is intendedto b e prevented by suitably regulating th'e fuel supply, .but sometimesregulation fails and in this eventpressures inside the boiler may becomedangerously high, the dangerously hi h"pre'ssure being caused by theabnormallyigh temperature. To .prevent this danger I- make a`safety`waste pipe connection from a hot part of the n boiler, and close theinlet from the boiler to the waste pipe with a fusible element adaptedto fail at al1-abnormally hi h temperature corresponding to an undesiraley high pressure. J'

I preferably use a disc form of fuse element 9U each disc being asection cnt from a bar, and am thus enabled to attain a uniformity anddefiniteness in the properties of the element and al cheapness and easeof manufacture that L union but which may obviously be straight orWithout union if desired.

In Figure l the L threads directly into the boiler while in Figure 2 itis threaded into a union at one of the outlets of a T 13 connectin theboiler to a hot Water supply pipe 14 of t e house.

If desired the L may be threaded directly into the top of the T in thesame way that it threads into the boiler at Figure 1.

In Figure 1 the inlet end of the L is counterbored and internallythreaded and my heat- Weakenedelement disc 15 is held against theshould-er 16 at the end of the counterbore, by a sleeve 17 threaded intothe open end of the fitting.

, Desirably the sleeve 17 projects beyond the end of the L and issuitably slotted at 18 upon opposite sides to provide a grip for ascrewdriver blade for screwing the sleeve in or out.

In Figure 5 the heat-weakened element disc 15 is held to place againstthe end of the nipple 19 by means of a cap member 20 having aI centralbore 21 of an desired size.

The size of the bore through the cap determines the rate of discharge ifthe heat-weakened element should fail and it should be sufficientlylarge but preferably no larger than that to insure adequate relief inthe event of heat-weakened element failure.

The outletV end of the discharge pipe 11 is desirabl located where anydischarge may be visib e so that a glance at the end of the pipe maydetermine whether or not the heatweakened element is properly sealingthe pipe from disch rge. Y

In Figure 2 t e L threads into the upper end of a union member 22connecting to one of the outlets 23 of the T feeding the hotJ watersupply line of the house and an outlet nipple 24 adapted to passlongitudinally throughthe T is threaded at its upperl end into the lowerend of the union member 22.

The mounting for the heat-weakened element in Figure 2 comprises asleeve 25 threadedupon the inlet end of the nipple 24 and havy ing anintermediate interior iiange 26. The

heat-weakened element is seated upon the ange 26 and held to place by asleeve 17 similar to thesleeve 17 of Figure 1.

In Figure 4 the union end of the `L makes union connection with the topof the T and the heat element 15 is clamped between the opposing membersof th'e union, asuitable compressible gasket 27 beingk provided to rial.

-Obviousl however, other forms of heatweakened e ements may be usedtrate this in Figure 3 where the heat element comprises a plug 30threaded 'into the end of t e L.

Usually material adapted to fail at the temperature which corresponds toa pressure beginnin to become dangerously hi h is not adapte to machineinto a threade plug so that the plug form of Figure 3 will usually bemelted and moulded to place in the taper of the service fitting and thenbe screwed tight.

In operation the discharge pipe does not function' unless some abnormalcondition arises permitting excessive heating within.

the heater. Such a condition might be due to failureof a thermostaticcontrol to correctly operate or to any cause whatever.

In the event of such excessive heating the temperature and the pressurevinside the boiler both become abnormally high until finally theheat-weakened element disc fails, with or without fusion, permitting adischarge of Water from inside the heater through the pipe 11 which Ihave called a waste pipe in that it will in practice nearly always beadapted to discharge to waste and which in any event is a discharge pipeso far as the boiler is concerned.

This discharge relieves the ressure and also normally brings cold waterrom the cold water supply line to replace that running away to wastethrough the pipe 11.

The abnormal condition for example at a thermostatic regulator, must becorrected and a new fusible element inserted before again operating theboiler.'

In view of my invention and disclosure variati'ons and modications tomeet individual whim or particularneed will doubtless beand I,therefore, claim all such in so far as they fall within the reasonablespirit and scope of my invention. l

Having thus described my invention what IV claim as new and desire tosecure by Letters Patent is 1. A iuid heater adapted to supply hotwater, a branching outlet fitting therefrom, a hot water supplyy pipefrom one of the branches a waste pipe from another-of the branches andaheat-weakened element in the inlet of the waste pipe adapted to fail ifsubjected to an abnormally high temperature.

2. water heater a T outlet fitting open to the boller at one en a hotWater supply pipe and I illusv weeen from one branch of the T, e,removable olischarge pipe mounted.' in the other enel of the' 'T havingen inlet inside the boiler enel e heetweekened. element normally closingthe et end/"and adapted to eil if subjected to ebnormall hightempersuture.v v

3. A uid heater, a branching outlet fitting therefrom, a. hot watersupply pi e from one of the branches, a union at emot er branch, a wastepipe having inlet from the branch et the union and a heat-weakenedelement snpported inthe inlet adapted? to fail if subjected toabnormally high temperature.'

LEUTE D.. LVEKN,

